1. Field of the Invention
The present invention relates to the field of managed objects, and more particularly to the field of distributed management expression processing of managed objects in a keyed data set.
2. Description of the Related Art
The Simple Network Management Protocol (SNMP) framework has been designed to facilitate the exchange of management information in a computer communications network. The Management Information Base (MIB) set forth as part of the SNMP framework defines the management information for a device in the computer communications network. In this regard, the MIB contains a collection of MIB objects otherwise referred to as managed objects that describe the characteristics of a device using SNMP. In particular, managed objects have been defined according to the rules set out in the Structure of Management Information (SMI) standard well-known in the art.
According to SMI, each managed object has two names—an object descriptor and an object identifier. The object descriptor is a conventional text name that provides a user recognizable reference to the object. The object identifier, in turn, provides a sequence of integers specifying a location of the managed object in a global object hierarchy maintained by the well-known international standards bodies ISO and ITS. Thus, the object identifier acts as a key to the managed object and can be manipulated in a programmatic fashion, while the object descriptor provides a human readable way to recognize the managed object.
It often can be important to work with values not present within an MIB. Consequently, one is left with the prospect of populating an already overflowing MIB with additional managed objects, or expressing the needed managed object as a function of existing managed objects. The Expression MIB set forth in Request for Comment (RFC) 2982 provides just such a facility. Specifically, RFC 2982 provides for externally defined expressions of existing MIB objects. In the Expression MIB, the results of an evaluated expression are MIB objects themselves that may be used like any other managed object in the MIB. These dynamically defined objects are thus usable anywhere any other MIB object can be used and can even be used by the Expression MIB itself, forming expressions of expressions.
The Expression MIB solution set forth in RFC 2982 can be complicated to implement, principally because the Expression MIB solution of RFC 2982 requires the user to provide numerous tables of input in a fixed format. Yet, the purpose of the Expression MIB is to simplify the specification and use of a managed object in the MIB without undertaking the complexity of adding the required managed object to the MIB. Thus, what is needed is a simplified way to express a required managed object from a potentially large data set amongst data in a keyed data set such as an MIB.